Reconstruction of late Pleistocene to mid-Holocene paleoenvironmental changes and human impact: the case study of “San Michele Cave” of Saracena (northern Calabria)

The San Michele Cave is located in north Calabria (southern Italy) close to Saracena village (CS). It is an open hypogeal karst landform shaped in the dolostone-limestone bedrock on the Pollino Massif. Since the Palaeolithic or Mesolithic to Early Bronze Age it was repeatedly settled and abandoned by men. We applied a multidisciplinary approach, based on geomorphological, pedological, geochemical and micromorphological analyses. In particular, we focused on reconstruction of late Pleistocene to mid-Holocene paleoenvironmental changes recorded in the pedosedimentary infilling of the cave. Various stages of geomorphic stability and pedogenesis, represented by dominant humus accumulation, carbonate leaching and reprecipitation, are alternated with sedimentary phases, which mainly emplaced thin-layered, (sandy-)loam deposits, with occasional very coarse debris related to rock-fall processes from the roof. Also important reworking processes from outside and/or inside the cave are evidenced by siliciclastic sediments, pedorelicts and/or papules, easily detected at the microscale in soil thin sections. Chronological constraints, obtained on the basis of archaeological findings and radiocarbon dates of charcoal fragments at different stratigraphic heights, permitted us to estimate approximate rates of sedimentary aggradation and soil formation. Moreover, the main soil features (e.g. CaCO3 concretions, clay coatings or papules) and pedogenic iron indices were interpreted as indicators of the local response of pedogenetic processes, weathering degree and geomorphic dynamics to climatic changes, which presumably also interacted with effects of human activities both in the cave and in the surrounding external environment, such as the anthropogenic degradation of the soil and vegetation cover.